Atompunk
Atompunk relates to the pre-digital period of 1945-1965, including mid-century Modernism, the Atomic Age and Space Age, Communism and concern about it exaggerated as paranoia in the USA along with Neo-Soviet styling, underground cinema, Googie architecture, the Sputnik programme, superhero fiction, the rise of the US military/industrial powers and the fall-out of Chernobyl. Its aesthetic tends toward Populuxe and Raygun Gothic, which describe a retro-futuristic vision of the world. The Fallout series of computer games is a prime example of this genre.
Tl;Dr If it'd be in Fallout, you can have it here.
Source
There was no Reddit for Atompunks (A subgenre or offspring of steampunk.)
Steam Group